Bioconjugates of inorganic nanoparticles have been extensively studied for various biological and medical applications such as bio-imaging and sensing, medical diagnostics, and drug delivery. In particular, gold nanoparticles heavily functionalized with thiol-modified oligonucleotides have shown great promise in DNA detection owing to their unusual DNA melting characteristics (i.e. sharp melting transitions and high binding constants) that originated from cooperative interactions of closely spaced DNA strands on the nanoparticle surfaces. Importantly, these unique properties have led to the development of DNA detection technologies with exceptionally high selectivity and sensitivity.
However, progress in extending these properties onto other types of nanoparticles has been hindered by the ability to obtain high density DNA on the surfaces of those nanoparticles. Accordingly, there exists a need for improved functionalization of nanoparticles.